Google has been scrambling for more than 24 hours to unclog a queue of messages sent to Gmail users that its Postini email filter incorrectly labeled as spam and quarantined. Check this article from PCWorld.com.

The company logged the problem shortly after 9 a.m. U.S. Eastern Time Wednesday on its Apps Status page. In the latest update to the issue, posted on Thursday at around 8 a.m., Google said it would start reprocessing copies of the quarantined messages “in the next hour” and that its engineers would start redelivering them “in small batches.”

“It’s then expected that it will take several hours until all messages are reprocessed,” the note reads.

It’s not clear from the information on the Apps Status page if this Postini problem is related to a message delivery delay Gmail users experienced on Tuesday.

Google didn’t immediately respond to a request for comment and more details, such as the cause and scope of the Postini problem. Postini services are used to secure Gmail as part of the Google Apps suite.

Google announced in mid-2012 that it would phase out the Postini email security cloud services, because it planned to progressively integrate the technology natively into Google Apps and into the optional Apps Vault email archiving, discovery and compliance service.

The process is still ongoing, according to the Postini Transition Resource Center page and accompanying timeline.